Creatinine Clearance (Serum Creatinine and Urine Volume-based)

What Is Creatinine Clearance Used For?

Creatinine clearance helps doctors evaluate kidney health by measuring how quickly creatinine—a waste product from muscle metabolism—is removed from your blood. It’s particularly useful for detecting early kidney damage or monitoring kidney function in people with chronic conditions like diabetes or high blood pressure.

How Is This Test Done?

You’ll provide a blood sample (serum) and a 24-hour urine collection. Blood is drawn once, while urine is collected over 24 hours to measure creatinine levels in both. Some labs may use a simplified 12-hour or shorter urine collection method.

Why Might You Need This Test?

Your doctor may order this test if you have symptoms like fatigue, swelling, or frequent urination, or if you have a condition that could affect kidney function (e.g., diabetes, high blood pressure, or a family history of kidney disease). It’s also used to guide treatment for chronic kidney disease.

What to Expect Before the Test

No special preparation is needed for the blood draw, but you should drink plenty of water the day of your urine collection to ensure a full sample. Avoid strenuous activity or medications that may affect kidney function 24 hours before testing.